Multiple magnet transducer with differential magnetic strengths

ABSTRACT

A dynamic magnet system, particularly useful for electrical generation, employs multiple magnets in polar opposition to each other for individual movement relative to a support structure. The magnets have a critical angle of displacement from a horizontal static position of less than 1 degree, with at least some of the magnets having mutually different properties. With different magnetic strengths, a greater movement is produced for both magnets in response to movements of the support structure, for particular ranges of magnetic strength ratios, than would be the case with equal magnets. The magnet movement can be translated into an electrical signal to power an operating system. Ultra low friction ferrofluid bearings can be used to establish static coefficients of friction between the magnets and support structure less than 0.02, enabling useful power generation from only slight movements of the support structure.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to dynamic magnet systems, and moreparticularly to multiple-magnet systems used to generate electric power.

[0003] 2. Description of the Related Art

[0004] Moving a magnet through a conductive coil induces a current flowin the coil. If the magnet is moved back and forth in a reciprocatingmotion, the direction of current flow in the coil will be reversed foreach successive traverse, yielding an AC current.

[0005] Several electrical generating systems have been disclosed thatmake use of reciprocating magnet movement through one or more coils. Forexample, in various embodiments of U.S. Pat. No. 5,347,185, one, two orthree rare earth magnets are positioned to move linearly back and forthrelative to one or more coils. The magnets can either be fixed and thecoil moved up and down relative to the magnet, as by wave action, thecoil can be fixed and the magnet moved relative to the coil as bypneumatic pressure, or the coil housing can be shaken or vibrated as bybeing carried by a jogger, to cause a reciprocating or oscillatingmotion of a magnet which moves within the coil. In one embodiment fourmagnets are provided in successive polar opposition, with the two endmagnets fixed and the middle magnets free to move back and forth alongrespective portions of a tube. The two middle magnets are separated fromeach other by the carrier for a middle coil, the carrier beingapproximately twice as wide as either of the middle magnets.

[0006] In U.S. Pat. No. 5,818,132, one embodiment discloses three movingmagnets that are suspended within a vertical tube in polar opposition toeach other and to end magnets, with a number of coils spaced along theoutside of the tube. To minimize friction between the moving magnets andthe tube, the tube is oriented vertically and moved up and down to movethe magnets relative to the coils, thus generating currents in thecoils. However, the vertical orientation interferes with the motion ofthe magnets, which have to fight gravitational forces in order to moverelative to the tube. The coupling of tube movements into the magnets isthus reduced.

SUMMARY OF THE INVENTION

[0007] The present invention provides a dynamic multiple magnet systemwhich achieves a greater coupling between a support structure for themagnets and the motion imparted to the magnets themselves. This enablesa greater electrical output for a given device size and weight, and alsoallows the magnets to be oriented for movement in a primarily horizontaldirection, thus greatly increasing their sensitivity to applied motion.

[0008] These improvements are achieved by orienting a plurality ofmagnets in polar opposition for individual movement relative to asupport structure, with at least some of the magnets having mutuallydifferent properties. The magnets can have different magnetic strengths,achieved by various means such as providing the magnets with differentmagnetizations or sizes. Equal size magnets having different degrees ofmagnetization, different sized magnets with equal unit degrees ofmagnetization, or blendings of the two can be used. Surprisingly, themagnet responses to an applied movement of their support structure aregreater than for two equal magnets having the average of their sizes andstrengths over specific magnetic strength ratios.

[0009] The magnets are preferably provided with ultra low frictionferrofluid bearings which establish static coefficients of frictionbetween the magnets and support structure less than 0.02. The ferrofluidpreferably has a viscosity less than 10 centipoise, and in a particularembodiment comprises a light mineral oil medium mixed with isoparaffinicacid.

[0010] The provision of ultra low friction bearings permits the magnetsto be disposed in a generally horizontal orientation, at which theirsensitivity to applied forces on the support structure is significantlyenhanced. With this orientation the magnets exhibit multiple oscillationmodes that effectively couple many different movements of the supportstructure into useful magnet motion. With one or more conductive coilspositioned to have their turns cut by the moving magnetic fields, anelectrical signal can be generated to power numerous kinds of operatingsystems. The critical angle of displacement for the magnets from ahorizontal static position is preferably less than 1 degree, and can beless than 10 minutes with an appropriate choice of ferrofluid bearings.

[0011] These and other features and advantages of the invention will beapparent to those skilled in the art from the following detaileddescription, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic diagram illustrating the use of a two magnetembodiment of the invention to provide power for an operating system;

[0013]FIG. 2 is a schematic diagram of a two-magnet embodiment withequal sized magnets having different magnetization;

[0014]FIG. 3 is a schematic diagram of a three-magnet embodiment of theinvention;

[0015]FIG. 4 is a calculated plot of magnet velocity as a function oftime for a two-magnet system with equal magnets, and

[0016]FIGS. 5 and 6 are calculated graphs relating relative energyoutput to relative magnet mass/magnetization differentials for strongand weak end magnet systems, respectively.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention provides for more effective and flexibleelectrical power generation than has previously been available inreciprocating or oscillating magnet systems. Electricity can beeffectively generated from very slight movements of the magnet supportstructure off a horizontal plane and/or movements in a horizontal plane.For example, a walking motion or other normal motions such as turning,tapping, bowing, or even riding in a vehicle that is subject tovibration, can easily generate useful amounts of electricity when thesupport structure for the magnets is held in the user's hand or in ashirt pocket, while slight off-horizontal movements due to wave or windaction can also be used for electrical generation.

[0018] The invention employs multiple magnets that move relative to acommon support structure. It is not restricted to the three magnetsrequired for the multi-magnet system of U.S. Pat. No. 5,181,132, butrather can employ virtually any number of magnets, including evennumbers. The requirement for a vertical orientation for the multi-magnetsystem of U.S. Pat. No. 5,181,132 is also eliminated, allowing for ahorizontal magnet motion that is much more sensitive to supportstructure movements.

[0019]FIG. 1 illustrates the use of the invention to provide power foran operating system. In this embodiment two moving magnets 2 and 4 movealong the axis of a support structure in the form of a tubularnon-magnetic enclosure 6. The magnets are in polar opposition to eachother, with their facing ends of like magnetic polarity. Thus, themagnets mutually repel each other when they come into proximity. Fixedmagnets 8 and 10 are positioned at opposite ends of the enclosure inpolar opposition to their nearest respective moving magnets 2 and 4. Theends of the moving and end magnets which face each other are also oflike magnetic polarity so that the adjacent magnets repel each other.

[0020] Magnet 2 is illustrated as having a unit size, while magnet 4 isillustrated as comprising two unit sizes. Since all of the magnet unitsare assumed in this embodiment to have equal magnetic strengths, theoverall magnetic strength of magnet 4 will be twice that of magnet 2.For slight impacts to the enclosure or slight off-horizontal enclosuremovements, the magnets 2 and 4 will slide along the enclosure 6 if thestatic coefficients of friction between the magnets and the enclosureare less than about 0.02. Magnet movement will generally not occur withhigher frictional coefficients in response to relatively gentleenclosure movements, such as those produced by placing the enclosure ina shirt pocket and walking with it. The use of two magnets in polaropposition to each other with ultra low friction bearings has been foundto greatly increase the responsiveness of magnet motion to enclosuremovements that are not at the natural frequency of the enclosure with asingle magnet, and/or are out of phase with the initial magnet motion.Surprisingly, it has been discovered that, when the two magnets havedifferent magnetic strengths, both magnets have a greater response toenclosure movements than do two equal magnets of intermediate magneticstrength. In other words, starting with two magnets of equal magneticstrength, increasing the strength of one and reducing the strength ofthe other will cause both magnets to oscillate faster in response toenclosure movements for particular ranges of strength ratios. Thisgreater responsiveness directly increases the amount of power that canbe generated with the system.

[0021] To achieve the desired low level of friction, ferrofluid bearingsare preferably employed as an interface between the magnets andenclosure. Ferrofluids are dispersions of finely divided magnetic ormagnetizable particles, generally ranging between about 30 and 150Angstroms in size, and dispersed in a liquid carrier. The magneticparticles are typically covered with surfactants or a dispersing agent.The surfactants assure a permanent distance between the magnet particlesto overcome the forces of attraction caused by Van der Waal forces andmagnetic interaction, and also provide a chemical composition on theouter layer of the covered particles which is compatible with the liquidcarrier and the chemicals in the surrounding environment. Ferrites andferric oxides employed as magnet particles offer a number of physicaland chemical properties to the ferrofluid, including saturationmagnetization, viscosity, magnetic stability and chemical stability.Several types of ferrofluids are provided by Ferrotec (USA) Corporationof Nashua, N.H. A summary of patents related to the preparation offerrofluids is provided in U.S. Pat. No. 6,056,889, while the use offerrofluid bearings in a moving magnet electrical generator is discussedin copending patent application Ser. No. ______, entitled “ElectricalGenerator With Ferrofluid Bearings”, filed on the same day as thepresent invention by the present applicants and also assigned toInnovative Technology Licensing, LLC, the assignee of the presentinvention. The contents of this copending application are herebyincorporated herein by reference.

[0022] The characteristics of the ferrofluid and magnets are related. Ifthe magnets have a relatively low magnetic field, a ferrofluid ofrelatively high magnetization should be used. The magnets' magneticfields will typically range from about 500-4000 Gauss, and themagnetization of the ferrofluid from about 50-400 Gauss.

[0023] The ferrofluid's frictional coefficient is roughly related to itsviscosity (measured in centipoise (cp)), but not directly. For example,a ferrofluid with a viscosity of 300 cp has been found to have a staticfriction coefficient of about 0.015, the EFH1 ferrofluid from Ferrotec(USA) Corporation has a viscosity on the order of 6 cp and a staticfriction coefficient of about 0.002, but a water based ferrofluid with aviscosity of 5 cp has been found to have a static friction coefficientof about 0.01. The higher friction coefficient for the somewhat lowerviscosity composition has been attributed to a surface tensionassociated with a water based solvent.

[0024] A preferred ferrofluid composition for the present invention hasa viscosity substantially less than 5 cp, actually less than 2 cp, andachieves an ultra low coefficient of static friction in the range of0.0008-0.0012. This is sensitive enough for a magnet on a beam to beginsliding when the beam is tilted only about 0.07 degrees off horizontal.This and other suitable ferrofluid compositions are discussed incopending patent application Ser. No. ______, entitled “MechanicalTranslator With Ultra Low Friction Ferrofluid Bearings”, filed on thesame day as the present invention by applicant Jeffrey T. Cheung, andalso assigned to Innovative Technology Licensing, LLC, the contents ofwhich application are hereby incorporated herein by reference. Thecomposition comprises a mixture of one part Ferrotec (USA) CorporationEFH1 light mineral oil ferrofluid mixed with from two to four parts ofisoparaffinic acid, stirred for 24 hours. Suitable sources ofisoparaffinic acid are Isopar G and Isopar M hydrocarbon fluids fromExxonMobil Chemical Corp.

[0025] Undiluted EFH1 ferrofluid could also be used. Undiluted EFH1composition has a greater weight bearing capacity than for the dilutedversion, but diluting the composition will retain sufficient weightbearing capability for most applications. Other ferrofluids with staticfriction coefficients up to about 0.02 could also be used, such asFerrotec (USA) Corporation type EMG805, a water based ferrofluid with astatic friction coefficient of about 0.01 and a viscosity of about 5 cp,since the power output achievable with a 0.02 static frictioncoefficient is still about 75% that achievable with a zero frictionsystem. At present the EMG805 composition is considerably more expensivethan the EFH1 composition and has a somewhat lesser load bearingcapability. In general, suitable ferrofluids will yield a critical angleof displacement from a horizontal static position of less than 1 degreeto initiate magnet movement, and with the mixture described about thecritical angle is less than 10 minutes.

[0026] Returning to FIG. 1, a ferrofluid within the enclosure 6 isnaturally attracted to the poles of magnets 2 and 4 to form beads 12, 14and 16, 18 around the end poles of magnets 2 and 4, respectively. Thisprovides an ultra low friction lubricant that allows the magnets tofreely slide with respect to the enclosure. The magnets will move inresponse to a tilting of the enclosure away from horizontal, ahorizontal movement of the enclosure, or more complex compoundmovements. The kinetic energy of the moving magnets is converted topotential energy as they approach their respective end magnets, and thenback to kinetic energy as they are repelled away from the end magnets.

[0027] A pair of conductive coils 20 and 22 are wound on respectivehalves of the enclosure 6. Alternately, a single coil encompassing thefull length of magnet movement within the enclosure could employed but,since the two magnets will often be moving in opposite directions,opposing currents would be induced in a single coil during these periodsthat would lower the system's overall efficiency.

[0028] Coils 20 and 22 are connected to respective full-wave bridgerectifying circuits 24 and 26, the outputs of which charge batteries 28and 30, respectively, within an overall operating system 32. Thebatteries provide power for an operating device 34, such as anenvironmental sensor, transmitter, flashlight or cellular telephone,that can be operated by mechanical inputs such as a walking motion, wavemotion or wind. Alternately, the bridge outputs can be connecteddirectly to the operating device if real time power is desired.

[0029]FIG. 2 illustrates an alternate embodiment of the invention, withjust the magnets and their enclosure shown for purposes ofsimplification, without coils or other circuitry. In this embodiment apair of magnets 36, 38 are again retained within a nonmagnetic enclosure40 by end magnets 42, 44 of opposing polarities. In this case themagnets are of equal size, but magnet 38 has a greater degree ofmagnetization and magnetic field strength, as indicated by doublemagnetization arrows, as opposed to a single magnetization arrow formagnet 36. The operation of this type of arrangement is generallyequivalent to that shown in FIG. 1, in which each of the magnet sectionshave equal unit field strengths, with one magnet having two sections andthe other having one. In both cases, both magnets will move faster inresponse to movements of the enclosure, for particular ranges of sizeand strength ratios, than would be the case with two magnets both havinga field strength equal to the stronger magnet of FIG. 2.

[0030]FIG. 3 illustrates a further embodiment with three magnets 46, 48and 50 within enclosure 52. In this example the magnets all havedifferent sizes/magnetic field strengths, with each riding on ultra lowfriction ferrofluid bearings. The largest magnet is shown disposedbetween the other two, but this order could be varied, as could theratios between the magnet sizes/field strengths, within the scope of theinvention. Two of the magnets could also be made equal, with the thirdmagnet having a different field strength. The invention can begeneralized to any plural number of magnets, with at least two havingdifferent magnetic strengths, although increasing the number of magnetsreduces the effective length of the enclosure left for magnet movement.

[0031]FIG. 4 is a calculated plot illustrating the multiple modes ofvibration that result from a plural magnet system with ultra lowfriction bearings. This plot was made with the magnets assumed to haveequal magnetic field strengths, and traces the velocity of one of themagnets as a function of time. The enclosure is assumed to have a lengththat would result in a natural frequency of 1 Hz for a single-magnetsystem. With two magnets there are multiple modes of oscillation,corresponding to the several velocity peaks which occur during each onesecond period, for each magnet. This makes the multiple magnet systemmore responsive to enclosure movements that do not match the system'snatural frequency and/or are out-of-phase with the initial magnetmovement. The increased responsiveness of multiple-magnet transducerswith ultra low friction bearings is discussed in detail in copendingpatent application Ser. No. ______, entitled “Multiple MagneticTransducer”, filed on the same day as the present invention by thepresent applicants and also assigned to Innovative Technology Licensing,LLC, the contents of which application are hereby incorporated herein byreference. Similarly, multiple oscillation modes are produced with themultiple magnets of different field strengths which are the subject ofthe present invention.

[0032]FIGS. 5 and 6 show the calculated energy outputs for two-magnetsystems, normalized to the energy output for a single-magnet system, asa function of the magnet mass and magnetization ratios. FIG. 5 presentsresults when strong fixed end magnets (11,400 Gauss) were assumed, andFIG. 6 for weak end magnets (3,800 Gauss). The results obtained formagnets of equal magnetic material but differing masses were equivalentto the results for magnets of equal mass but differing magneticstrengths. The following assumptions were made:

[0033] Stronger magnet size: 2.54 cm. diameter, 1.27 cm. long.

[0034] Stronger magnet strength: 11,400 Gauss.

[0035] Tube length: 15.24 cm.

[0036] End magnet size: 0.95 cm. diameter, 0.635 cm. long.

[0037] Acceleration applied to tube: 1 meter/sec./sec. alternating for0.5 sec. forward and 0.5 sec. backward, for a 1 Hz frequency (simulatingan arm swing).

[0038] Frictionless system.

[0039] The two-magnet systems produced greater energy outputs than thesingle-magnet systems over particular ranges of mass or magnetizationratio, with the range depending upon the end magnet strength. With thestrong end magnets of FIG. 5 a significantly enhanced output wascalculated for ratios of about 0.075-0.2, while with the weak endmagnets of FIG. 6 a significantly enhanced output was calculated forratios of about 0.35-0.6, with a lesser peak at about 0.04. Since theapplied acceleration alternated at a frequency near the single magnetsystem's resonant frequency, even better results could be expected atfrequencies further removed from the resonant frequency, or for randominputs.

[0040] It is also significant that greater energy outputs werecalculated for the two-magnet system with different magnet sizes orstrengths than for a two-magnet system with equal magnet sizes orstrengths (corresponding to a ratio of 1). With the system of FIG. 5this occurred over generally the same range of ratios as when comparedto a one-magnet system, while in FIG. 6 this occurred over the fullratio range.

[0041] The invention has many applications, some of which includeproviding power for cellular telephones, emergency transmitters andenvironmental sensors, and electrical generation and battery chargingsystems in general.

[0042] While several embodiments of the invention have been shown anddescribed, numerous variations and alternate embodiments will occur tothose skilled in the art. For example, greater numbers of magnets couldbe employed than in the systems illustrated, or different ultra lowfriction lubricants than the specific compositions mentioned could beused. Also, instead of placing the magnets inside a housing and windingthe coils around the outside of the housing, the elements could bereversed with coils inside a housing and a toroidal-shaped magnetoutside. Accordingly, it is intended that the invention be limited onlyin terms of the appended claims.

We claim:
 1. A dynamic magnet system, comprising: a support structure,and a plurality of magnets oriented in polar opposition for individualmovement relative to said support structure, at least some of saidmagnets having mutually different properties.
 2. The dynamic magnetsystem of claim 1, said at least some magnets having different magneticstrengths.
 3. The dynamic magnet system of claim 2, said at least somemagnets having substantially equal sizes.
 4. The dynamic magnet systemof claim 1, said at least some magnets having different sizes.
 5. Thedynamic magnet system of claim 4, said at least some magnets havingsubstantially equal unit magnetic strengths.
 6. The dynamic magnetsystem of claim 1, further comprising respective bearings establishingstatic coefficients of friction between said magnets and said supportstructure less than 0.02.
 7. The dynamic magnet system of claim 1,further comprising ferrofluid bearings between said magnets and saidsupport structure.
 8. The dynamic magnet system of claim 7, saidferrofluid having a viscosity less than 10 centipoise.
 9. The dynamicmagnet system of claim 8, said ferrofluid comprising a light mineral oilmedium mixed with isoparaffinic acid.
 10. The dynamic magnet system ofclaim 1, further comprising a conductor oriented with respect to saidsupport structure and magnets so that movement of said magnets inducesan electrical signal in said conductor.
 11. The dynamic magnet system ofclaim 10, said conductor comprising at least one coil wound on saidsupport structure, said support structure being nonconductive.
 12. Thedynamic magnet system of claim 10, further comprising an operatingsystem powered by said signal.
 13. The dynamic magnet system of claim 1,further comprises a pair of end magnets limiting the travel of saidmoving magnets, said end magnets oriented in polar opposition to thenearest respective moving magnet.
 14. The dynamic magnet system of claim1, said magnets having multiple oscillation modes relative to saidsupport structure.
 15. The dynamic magnet system of claim 1, saidsupport structure orienting said magnets for movement in a primarilyhorizontal direction.
 16. The dynamic magnet system of claim 1, saidmagnets oriented for movement along a common axis.
 17. The dynamicmagnet system of claim 1, said system having a critical angle ofdisplacement for said magnets from a horizontal static position of lessthan 1 degree.
 18. The dynamic magnet system of claim 17, wherein saidcritical angle is less than 10 minutes.
 19. An energy harvester,comprising: a support structure, a plurality of magnets oriented inpolar opposition to oscillate relative to said support structure inmultiple oscillation modes, at least some of said magnets havingmutually different properties, respective bearings establishing staticcoefficients of friction between said magnets and said support structureless than 0.02, and a conductor oriented with respect to said supportstructure and magnets so that oscillation of said magnets in response toa movement of said support structure induces an electrical signal insaid conductor.
 20. The energy harvester of claim 19, said at least somemagnets having different magnetic strengths.
 21. The energy harvester ofclaim 20, said at least some magnets having substantially equal sizes.22. The energy harvester of claim 19, said at least some magnets havingdifferent sizes.
 23. The energy harvester of claim 22, said at leastsome magnets having substantially equal unit magnetic strengths.
 24. Theenergy harvester of claim 19, said bearings comprising a ferrofluid. 25.The energy harvester of claim 24, said ferrofluid having a viscosityless than 10 centipoise.
 26. The energy harvester of claim 24, saidferrofluid comprising a light mineral oil medium mixed withisoparaffinic acid.
 27. The energy harvester of claim 19, furthercomprising an operating system powered by said signal.
 28. The energyharvester of claim 19, said support structure orienting said magnets formovement in a primarily horizontal direction.
 29. An energy harvester,comprising: a support structure, a plurality of magnets oriented inpolar opposition to oscillate relative to said support structure inmultiple oscillation modes, at least some of said magnets havingmutually different properties, and a conductor oriented with respect tosaid support structure and magnets so that oscillation of said magnetsin response to a movement of said support structure induces anelectrical signal in said conductor, wherein said harvester has acritical angle of displacement for said magnets from a horizontal staticposition of less than 1 degree.
 30. The energy harvester of claim 29,wherein said magnets have different magnetic strengths.
 31. The energyharvester of claim 29, wherein said critical angle is less than 10minutes.
 32. The energy harvester of claim 29, further comprising anoperating system powered by said signal.
 33. A dynamic magnet system,comprising: a support structure, and an even number of magnets orientedin polar opposition to individually move relative to said supportstructure along a common axis, at least some of said magnets havingmutually different properties.
 34. The dynamic magnet system of claim33, said at least some magnets having different magnetic strengths. 35.The dynamic magnet system of claim 34, said at least some magnets havingsubstantially equal sizes.
 36. The dynamic magnet system of claim 33,said at least some magnets having different sizes.
 37. The dynamicmagnet system of claim 36, said at least some magnets havingsubstantially equal unit magnetic strengths.
 38. The dynamic magnetsystem of claim 33, further comprising respective bearings establishingstatic coefficients of friction between said magnets and said supportstructure less than 0.02.
 39. The dynamic magnet system of claim 33,further comprising ferrofluid bearings between said magnets and saidsupport structure.
 40. The dynamic magnet system of claim 39, saidferrofluid having a viscosity less than 10 centipoise.
 41. The dynamicmagnet system of claim 39, said ferrofluid comprising a light mineraloil medium mixed with isoparaffinic acid.
 42. The dynamic magnet systemof claim 33, further comprising a conductor oriented with respect tosaid support structure and magnets so that movement of said magnetsinduces an electrical signal in said conductor.
 43. The dynamic magnetsystem of claim 42, further comprising an operating system powered bysaid signal.
 44. The dynamic magnet system of claim 33, said magnetshaving multiple oscillation modes relative to said support structure.45. The dynamic magnet system of claim 33, said support structureorienting said magnets for movement in a primarily horizontal direction.46. The dynamic magnet system of claim 33, said system having a criticalangle of displacement for said magnets from a horizontal static positionof less than 1 degree.
 47. The dynamic magnet system of claim 46,wherein said critical angle is less than 10 minutes.
 48. A dynamicmagnet system, comprising: a support structure, a plurality of magnetsoriented in polar opposition to move relative to said support structure,at least some of said magnets having mutually different properties, andrespective bearings establishing ultra low static coefficients offriction less than 0.02 between said magnets and said support structure,said support structure orienting said magnets for primarily horizontalmovement.
 49. The dynamic magnet system of claim 48, said at least somemagnets having different magnetic strengths.
 50. The dynamic magnetsystem of claim 49, said at least some magnets having substantiallyequal sizes.
 51. The dynamic magnet system of claim 48, said at leastsome magnets having different sizes.
 52. The dynamic magnet system ofclaim 51, said at least some magnets having substantially equal unitmagnetic strengths.
 53. The dynamic magnet system of claim 48, saidbearings comprising a ferrofluid.
 54. The dynamic magnet system of claim53, said ferrofluid having a viscosity less than 10 centipoise.
 55. Thedynamic magnet system of claim 53, said ferrofluid comprising a lightmineral oil medium mixed with isoparaffinic acid.
 56. The dynamic magnetsystem of claim 48, further comprising a conductor oriented with respectto said support structure and magnets so that movement of said magnetsinduces an electrical signal in said conductor.
 57. The dynamic magnetsystem of claim 56, further comprising an operating system powered bysaid signal.
 58. The dynamic magnet system of claim 48, said magnetshaving multiple oscillation modes relative to said support structure.59. A dynamic magnet system, comprising: a support structure, and aplurality of magnets oriented in polar opposition to move relative tosaid support structure, at least some of said magnets having mutuallydifferent properties, said support structure orienting said magnets forprimarily horizontal movement, wherein said system has a critical angleof displacement for said magnets from a horizontal static position ofless than 1 degree.
 60. The dynamic magnet system of claim 59, whereinsaid magnets have different magnetic strengths.
 61. The dynamic magnetsystem of claim 59, wherein said critical angle is less than 10 minutes.62. The dynamic magnet system of claim 59, further comprising aconductor oriented with respect to said support structure and magnets sothat movement of said magnets induces an electrical signal in saidconductor.
 63. The dynamic magnet system of claim 62, further comprisingan operating system powered by said signal.
 64. The dynamic magnetsystem of claim 59, said magnets having multiple oscillation modesrelative to said support structure.